Add graphical graphs to docu flux

[dr0i]

Create a graphical graph out of https://github.com/metafacture/metafacture-documentation/blob/master/flux-commands.md regarding the signature . This could help people to understand what modules can be chained.

[fsteeg]

We were planning a slightly different approach to improve flux commands documentation in metafacture/metafacture.github.io#10.

[dr0i]

Added a branch which helps to generate such a graphical graph presentation.

It seems rather unlikely that this graph is helping users to find what is to be piped to what.
Maybe the SVG can serve as ... something? It show how many flux modules we have. It shows the complexity when it comes to piping.
WDYT @TobiasNx and @maipet ?